Valve



J. D. MAXWELL.

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i APPLICATION FILED APR.15, 1921. Y 1,420,652. K Patented June 27, 1922.

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J'AMES D. MAXWLL, 0F BROOKLYN, NEW YORK.

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Specification of Letters Patent.

Patented June 27, 1922.

Application led April 15, 1921. Serial No. 461,493.

T o all 'whom it may concern:

Be it known that I, JAMES D. MAXWELL, a subject of the King of Great Britain, and a resident of Brooklyn, Kings County, and State of New York, have invented certain new and useful Improvements in Valves, of

which the following is a specification.

My invention relates particularly to valves of the high pressure or heavy duty type, such as are used in the steam mains in power plants-and the like.

The objects of the invention are to provide a valve of this type which will be safe and secure, which can be easily operated without danger of straining the parts and which will be tight-litting in both its open and its closed positions.

In the drawing accompanying and forming part of this specification, I have illustrated the invention embodied in one of its practical, commercial forms, but Wish it understood that the structure may be varied more or less 4without departure from the true spirit and scope of the invention asherein-A after defined and claimed.

Figure 1A in the drawing is a vertical sectional view of the valve in its closed condition.

Figure l2 is a similar view showing the valve parts in the fully open condition. v

l4`ig'ure 3 is a horizontal sectional view on substantially the plane of line 3-3 of Figure 1.

y The body or casing 5 of the valve is provided with a passage therethrough, intercepted by a cross partition 6 separatingthe passage into inlet and outlet sides, said partition having an opening 7 therethrough.

and arranged to` be shifted toward and away from their cooperating seats on the turning vof said valve stem by the hand wheel 13.

The connections by which theseresults are eected involve the screw-threading of the lower end of tlewalve stem into the lower valve disc, as indicated at14 and the engagement of the upper valve disc between shoulders 15, 16 on the valve stem.. The upper shoulder 15 Ais shown as an integral part formed on the stem and having a beveled upper face 17 to engage a corresponding shaped beveled seat 18 on the valve casing. The lower shoulder 16is shown in the form of a collar adjustably securedon the valve stem by a set screw 19.

The lower valve`disc is held against turning by having outstanding guide lugs 20 operating in the guide slots 21 in the annular wall 22 upstanding from the base of the valve casing. This upstanding annular wall also provides a seat for the spring 23 which operates against the underface of the lower valve element tending to thrust it toward lts seat. v

To provide access to the opposite faces of ythe cross partition 6 for machining the valve seats 8 and 9 at the opposite ends of the passage 7, I have shown the valve body as made with removable top and bottom caps 24, 25, respectivel detachably secured to the body of the va ve and adapted when removed toV give full access to the upper and lower valve elements and their respective sea-ts. A suitable packing gland is provided for the valve stem, such as I have indicated at 26.

, When the valve is closed, as in Figure 1, it will be seen that a double seal is provided, one at each end =of the opening or passage 7, and it will furthermore be evident that no injury can result from setting up the valve too tightly, since the closing ofthe valve simply involves the bringing of the valve elements together into clamping engagement with the opposite vsides. of the partition wall. In other words, the lpartition` wall is simply clamped betweenv the valve elements and is not subjected to any material thrustl in one direction or the other. When the valve stem is turned to open the valve, the first effect is for the stem or shank to unscrew from the lower non-rotating valve element and to thereby lift the upper valve Velement from its seat. This motion will continue until the beveled shoulder engages in its conical seat 18, and wheny this occurs it will be seen that the further rotation of the stem will result in the screw thrusting the lower valve element down away from its seat, as indicated in Figure 2. Before this lower valve element is unseated, and hence before the valve is actually opened, the shoulder on the stem forms a seal with the valve casing and so said chamber having a port 28 extending to the face of the valve and hence to the space between the valve elements.

What I claim is:

l. In a valve, a valve casing having a wall with a passagetherethrough and valve seats at the opposite ends of said passage, valve elements at the opposite sides of said Wall for cooperation with said valve seats, a valve operating stem having a screwthreaded connection with one of the valve elements, said valve element being chambered to receive the stem and having a port extending from such chamber to the face of the valve.

2. In a valve, a valve casing having a Wall provided with a passage and With valve seats at opposite ends of the same, cooperating valve elements for engagement with said valve seats, one of said valve elements having a pressure relieving chamber and a port extending from the face of the same to .said chamber.

3., In combination, a valve casing having a partition with a passage therethrough and valve seats at the opposite ends of the same, opposed valve elementsv for cooperation with said seats, one of said elements having a guide lug, an annular wall on the casing slotted to receive said guide lug, a spring seated within saidvannular wall and bearing on the valve element and a valve stem having operative connection with the valve elements.

4, In a valve, a valve casing having a passage with valve seats at opposite ends of vthe same, valve elements for cooperation with said valve seats, a valve operating stem having a 'screw-threaded connection with one ofl the valve elements, said valve element being chambered to recelve the stem and constructed to relieve pressure from such chamber, the other valve element being carried by and movable with the stem, the valveV casing havin a passage in which the valve stem is longitudinally shiftable with a seat at the inner end of said valve stem passage and the valve stem having a shoulder to cooperate with said last mentioned seat in the longitudinal movement of the stem to form a leak-proof joint and thrust shoulder for the stem.

In Witness whereof, I have hereunto set my hand this 12th day of April, 1921.

JAMES n. MAXWELL. 

